[A case of meningoencephalitis caused by persistent Epstein-Barr (E-B) virus infection].

A 44-year-old man had several episodes of tingling sensation in his lower extremities, head and face over 1 year and presented mental disturbance 2 months prior to admission. He additionally suffered from dysuria and acute onset of gait disturbance 18 days before admission. Physical and neurological examination revealed marked splenomegaly, stupor, abnormal behavior, spastic tetraparesis and sphincter disturbances, and meningoencephalitis was suspected. There was lymphocytosis in peripheral blood, some of which showed atypical morphology. CSF examination revealed increased protein content and mononuclear pleocytosis. The titers of antibodies against E-B virus were elevated as follows; VCA IgM (X320), VCA IgG (X20,480), EA (X10,240) and EBNA (X10) in serum, and VCA IgM (X4), VCA IgG (X160), EA (X40) and EBNA (less than 1) in CSF. CT and MRI examination revealed ring enhanced lesion adjacent to left lateral ventricle with surrounding diffuse edema. Administration of intravenous glycerol and oral prednisolone induced substantial improvement in sensory, mental and sphincter disturbances and brain CT findings but not in splenomegaly and pyramidal tract signs. Antibody titer against VCA IgM also decreased. After withdrawal of prednisolone, CSF and CT findings worsened, and the antibody titer became elevated again, and CSF and CT findings improved by readministration of prednisolone. From the above signs and laboratory data, especially continuous elevation of antibody titer against E-B VCA IgM for as long as 1 year, this case was considered to be a meningoencephalitis caused by persistent E-B virus infection.